Comal and Hays Counties, Texas
The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Comal and Hays Counties, Texas.
| Soil Map Unit | Acres | Drainage | Hydro Group | Dwellings | Septic |
|---|---|---|---|---|---|
| Comfort-Rock outcrop complex, 1 to 8 percent slopes | 154K | Well drained | D | Very limited | Very limited |
| Brackett-Rock outcrop-Comfort complex, 1 to 8 percent slopes | 110K | Well drained | D | Very limited | Very limited |
| Rumple-Comfort, rubbly association, 1 to 8 percent slopes | 106K | Well drained | D | Very limited | Very limited |
| Brackett-Rock outcrop-Real complex, 8 to 30 percent slopes | 105K | Well drained | D | Very limited | Very limited |
| Real-Comfort-Doss complex, 1 to 8 percent slopes | 44K | Well drained | D | Very limited | Very limited |
| Eckrant-Rock outcrop association, 8 to 30 percent slopes | 33K | Well drained | D | Very limited | Very limited |
| Houston Black clay, 1 to 3 percent slopes | 20K | Moderately well drained | D | Very limited | Very limited |
| Bolar clay loam, 1 to 3 percent slopes | 16K | Well drained | C | Very limited | Very limited |
| Doss silty clay, moist, 1 to 5 percent slopes | 16K | Well drained | D | Very limited | Very limited |
| Heiden clay, 3 to 5 percent slopes, eroded | 16K | Well drained | D | Very limited | Very limited |
| Branyon clay, 0 to 1 percent slopes | 13K | Moderately well drained | D | Very limited | Very limited |
| Krum clay, 1 to 3 percent slopes | 13K | Well drained | C | Very limited | Very limited |
| Water | 12K | D | Not rated | Not rated | |
| Denton silty clay, 1 to 3 percent slopes | 11K | Well drained | D | Very limited | Very limited |
| Sunev clay loam, 1 to 3 percent slopes | 9K | Well drained | B | Not limited | Somewhat limited |
| Lewisville silty clay, 1 to 3 percent slopes | 9K | Well drained | C | Very limited | Very limited |
| Real gravelly loam, 1 to 8 percent slopes | 9K | Well drained | D | Very limited | Very limited |
| Purves clay, 1 to 5 percent slopes | 8K | Well drained | D | Very limited | Very limited |
| Heiden clay, 1 to 3 percent slopes | 7K | Well drained | D | Very limited | Very limited |
| Tinn clay, 0 to 1 percent slopes, frequently flooded | 7K | Moderately well drained | D | Very limited | Very limited |
What This Means
Building & Foundations
About 97% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, flood-prone areas. A geotechnical assessment is recommended before building.
Septic Systems
About 97% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.
Gardening & Agriculture
Drainage is generally favorable for gardening. Adding compost and mulch will improve fertility and water retention. Test your soil's pH before planting — most vegetables prefer 6.0-7.0.